Duplex electron-discharge device



June ,10, 1930.- w. J. DESMOND 1,762,960 DUPLEX ELECTRON DISCHARGEDEVICE Filed Aug. 1, 1924 I K B.

' v INVENTORY WM/mm 1 Des/720170 B) TTOR/VE V Patented in... 10, 1930WILLIAM J esi/tonnes nnniusongnnwannsnx f y UPLEX ELECTRON-DISCHARGEDEVICE Application filed. August 1, 1924. Y Serial No. 729,472. r 7

The object of thejpresentinvention is to provide an electron tube forradio use that Will have a much longer useful lifethan the tubes of thischaracter'at present in use.

having aibaseat each end a-dapted'to make external connections with thecircuits of a radio receiving or transmitting, set. Within the envelopeare two stems for mounting the.

electrodes, one stem being at each end of the ments, one m-ountedon eachstem; a single anode and a single control electrode each of which isprovided with a double set' of lead Wires one set being mounted on eachstem and connecting into the appropriateexternal circuits through eitherbase. Such a tube, being a duplex tube, is capable of being adjustedinto the tube sockets of a radio set at either end.

In order. that the invention may be clearly understood, I haveillustrated it by the accompanying drawings. -Figure 1 shows themounting of the filaments within the tube.

Figure 2 shows a detail of the construction representing the mounting ofthe two filaments upon their respective stems.

As will be evident from the drawing, there is a base witha full set ofcontact prongs at be evident that I haveprovide-d astem' at each endofthe tube through each of which are sealed a full set of leads from theelectrodes to the prongs of the base.

Referring to Figure 1, which showsthe mounting of the'filanient, it willbe noted that the stem A is set'at an angle preferably at right angle tothestem The filament 'leads B'of the stem A are sealed-through the pressof the stem and to this afilament which may be, asshown in the drawing,of the hair pin type, is welded. "A similar construction of the filamentleads B" is' also shown. The filament D, which is, welded to the leads13'. passes over the filament D so 'The tube comprises an evacuatedenvelope, manner the filament D is held taut. by

each end of the closed envelope. It will also departing from thethattheloops orpoints of the hair in fin ments interlink withouttouching. The fila-f ment D is held taut bya hook C which is sealed intothe press of the stem A. In like t Y e 350 hook C-which is sealedintothestem A. 7

Theangular setof the glass stems permits ,the.-mounting of the hair pinfilament in, such amanner that the filament wires may;

inter-link without interference with each other. I g

The grid and plate are placed about the two filaments. I prefer toconstruct both of I these electrodes in cylindrical form mountedcoaxially, but I ma employ any of the forms o at present in use. Lead inwires from these electrodes are sealed through each of the. I

stems and extend to the posts or prongs of" each base adapted to formexternal connections into the appropriate circuits of the ra; 5 dioapparatus. When the tube so constructed is in use one base is fittedinto the socket of the radio apparatus and the..other base with its leadin wires is out of use.

the tube may, beused on one base until the filament is burned. outand itmay then be desired, be covered with a plugof bakelite, rubber orsimilar insulating material.

In the drawings Figure 1' and Figure 2,'I,

l have shown one form of the tube only. Itso will be evident,'however,that other arrange ments of the parts may be made Without principle ofthis invention. l

I claim is 1. In an electron dischargedevi'ce comprising asealed'evacuated glass envelope, hav-' ing stem presses sealed into saidenvelope at 1 opposite ends thereof, said stems being set 90 Theadvantage of this .70 invention cons lstsprimarily in the fact that"Having thus describedmy invention, what 7 at an angle t the longitud 0each other but coincident With inal axis of the tube and each stemhaving a hair pin filament mounted thereon, the said filamentsinterlinking With- 5 out interference with each other.

2. An electron discharge device having stem presses at opposite ends,the planes of which are at an angle to each other, a plu rality of coldelectrodes mounted in each stem, a filament in each stem interlinkedwith the filament in the other stem and means to'hold'the filaments outofcontact.

In'testimo my hand thi ny whereof, I have hereunto-set s 11th day ofJuly, 1924:. WILLIAMJ. ,DESMOND.

